Topic 1- Classification, Variation and Inheritance Flashcards
What are the 5 kingdoms?
- Animalia
- Plantae
- Fungi
- Prokaryote
- Protoctista
Properties of Animalia?
- multicellular
- do not have cell walls
- do not have chlorophyll
- feed heterotrophically
Properties of Plantae?
- multicellular
- have cell walls
- have chlorophyll
- feed autotrophically
Properties of Fungi?
- multicellular or unicellular
- have cells walls
- do not have chlorophyll
- feed saprophytically (extracellular digestion of dead organic matter)
Properties of Prokaryote?
- unicellular
- do not have a nucleus
Properties of Protoctista?
- unicellular
- do have a nucleus
What are the 5 verterbrate classes?
- fish
- amphibians
- reptiles
- birds
- mammals
Properties of fish?
- have wet scales
- have gills
- lay eggs (oviparous)
- cold blooded (poikilotherms)
Properties of amphibians?
- have moist, permeable skin
- young have gills, adults have lungs
- lay eggs in water or damp places (oviparous)
- cold blooded (poikilotherms)
Properties of reptiles?
- have dry, scaly skin
- have lungs
- lay eggs (oviparous)
- cold blooded (poikilotherms)
Properties of birds?
- have feathers and a beak
- have lungs
- lay eggs (oviparous)
- warm blooded (homeotherms)
Properties of mammals?
- have hair or fur on skin
- produce milk
- have lungs
- give birth to live offspring (viviparous)
- warm blooded (homeotherms)
Based on what 3 things do scientists place organisms into groups?
- the way in which they absorb oxygen (lungs or gills or skin)
- the way in which they reproduce (oviparous or viviparous)
- they way in which they regulate their temperature (homeotherms or poikilotherms)
Why is it important to classify organisms?
- So scientists can study groups of similar organisms
- So scientists can identify habitats or species that need conservation
- So that conservation can lead to greater biodiversity (variety of different types of organisms in an ecosystem)
what are adaptations?
adaptations are special features or types of behaviour that make an organism well suited to their environment
what are adaptations of the polar bear? (cold terrestrial climate)
- insulating fat layer beneath skin
- large feet to spread weight on the ice
- white coat so it is camouflaged
what are the adaptations of a camel? (hot terrestrial climate)
- body fat stored in hump
- loses very little water through heat and sweating
- sandy coat so it is camouflaged 2
what are the adaptations of a fish? (aquatic environment)
- streamlined shape to travel quickly through water
- gills to obtain dissolved oxygen in water
- gills have large surface area so more oxygen can be absorbed
what are the adaptations of the water lily? (aquatic environment)
- flexible stems so it can bend in the water’s current
- underwater leaves are streamlined
- leaves grow on the surface of the water to maximise photosynthesis
what are the adaptations of the cactus? (hot terrestrial environment)
- thick waxy surface to reduce water loss
- stomata only open at night to reduce water loss
- spines to protect it from predators
what is an extreme habitat?
an extreme habitat is a habitat with conditions outside those in which normal organisms live
give 2 examples of an extreme habitat?
- hydrothermal vents
- the Antarctic
how are organisms adapted to live in hydrothermal vents? (e.g. tubeworms, pompeii worms)
- being able to cope with high pressure and temperature
- have highly developed senses other than sight
how are organisms adapted to live in the Antarctic? (penguins)
- compact shape so they lose little heat
- thick layer of insulating fat under skin
- often huddle in large, tightly packed groups to retain heat
what is variation?
variation is the differences between individuals of the same species
give examples of complications within classification?
- hybridisation in ducks
- ring species, e.g. salamanders on the US West Coast
what is hybridisation in ducks?
hybridisation in ducks occurs when two different species of duck breed and produce a fertile duck which could be considered as a different species altogether
what is ring species?
ring species are overlapping populations of two closely related species that can only interbreed in the overlapping region
what is speciation?
speciation is the process of evolution by which new species form
variation occurs due to what two factors?
- genetic causes
- environmental causes
what is continuous variation?
continuous variation is variation that does not fit into groups, and values have a range/ they cannot be measured (e.g. height, weight)
what is discontinuous variation?
discontinuous variation is variation that fits into a small number of clearly defined groups (e.g. eye colour, blood type)
what is theory of evolution?
evolution is the theory that all living organisms that exist today developed from simple life forms
who came up with the theory of evolution?
CHARLES DARWIN!! WOOOOO!!!
how do scientists validate their work?
- peer review processes
- record findings in scientific journals
- attending scientific conferences
what are the 6 steps of natural selection? (VOSSIG)
- Variation (between organisms)
- (leads to) Over-production
- (which leads to) Struggle for existence
- Survival (of the fittest, best individuals survive)
- Inheritance (good adaptations passed on)
- Gradual change (they evolve over time)
each cell in the human body has how many chromosomes?
46 individual chromosomes (23 pairs)
what is an allele?
an allele is a different version of the same gene (e.g. for eye colour- blue, green, brown etc)
what is a dominant allele?
a dominant allele that always controls the development of the characteristic, even if it is only present in one of the chromosomes in a pair
what is a recessive allele?
a recessive allele that only controls the development of the characteristic if it is present in both of the chromosomes in a pair
what does the term ‘homozygous dominant’ mean?
it means that the individual has a dominant allele on both of the chromosomes in a pair
what does the term ‘homozygous recessive’ mean?
it means that the individual has a recessive allele on both of the chromosomes in a pair
what does the term ‘heterozygous’ mean?
it means that there is one dominant allele and one recessive allele present on the chromosome
what is a family pedigree?
a family pedigree is basically a family tree/ chart that shows the presence or absence of specific alleles from one generation to the next
what is ‘monohybrid inheritance’?
an example of monohybrid inheritance is simple genetic crosses that can be performed to investigate the mechanism of inheritance
how can genetic crosses be shown?
- punnett square
- genetic cross diagram
what are genotypes?
genotypes are the letters used to simplify words (e.g. for earlobes, combinations of E and e are used)
remember: capital letters are used for dominant alleles and lower case letters are used for recessive alleles
what are phenotypes?
phenotypes are the physical characteristics (e.g. attached earlobes)
what is cystic fibrosis?
cystic fibrosis is a genetic disorder that affects cell membranes
what are the symptoms/characteristics of cystic fibrosis?
- not being able to digest food properly
- airways clogged with mucus
- more susceptible to chest infections, including pneumonia
- shorter life expectancy (40-50 years)
how can cystic fibrosis symptoms be treated?
- enzyme tablets
- chest therapy
- antibiotics
is there a cure for cystic fibrosis?
no, there is no cure
what is sickle cell disease?
sickle cell disease is an inherited disorder that affects red blood cells; instead of being their normal, biconcave shape, they look more like sickles.
what are the symptoms/characteristics of sickle cell disease?
- red blood cells are no longer able to carry oxygen, making breathing difficult
- red blood cells can get stuck in capillaries, which can stop blood reaching tissues, leading to great pain and may cause tissue damage
- also may cause dizziness
what is a carrier?
a carrier is a person who only have one faulty allele. however, a disorder can be inherited by offspring if both parents are carriers.
